A touch screen is an input equipment enabling a user to directly input a command of the user by selecting command contents displayed on a screen of an image display and the like by hand or with an object, and when the user is in direct contact with the touch screen by hand or with the object, the touch screen detects a touch point and drives a liquid crystal display according to the command of a selected icon to realize specific displaying.
The existing touch screens are mainly divided into capacitive touch screens and electromagnetic touch screens according to different working principles; wherein, the capacitive touch screens identify touch position through received touch signals (namely, electrical signals), while the electromagnetic touch screens identify touch position through received touch signals (namely, electromagnetic signals from electromagnetic needles). At present, an independent capacitive touch screen is generally assembled on the outer side (namely, one side facing a viewer) of a liquid crystal display, so as to receive the electrical signals corresponding to the touch operations; and an independent electromagnetic touch screen is assembled on the outer side of the liquid crystal display or in the back of a backlight module.
However, the present independent capacitive touch screen and independent electromagnetic touch screen are externally mounted on the liquid crystal display, so that the liquid crystal display with capacitive and electromagnetic touch functions is relatively thick.